Improved modular panoramic night vision goggles

ABSTRACT

A night vision goggle system is shown, including optical modules, a heads-up display (HUD) module, and a camera module. Each module may be added to and removed from the system without structural, electrical, or optical damage to itself or the remaining modules. Each optical module takes input light at one end and provides an intensified image at the other. A heads-up display module (HUD) can provide an informational display in any of at least two of the optical modules or both. A camera module is capable of recording both the intensified image produced by a particular optical module, as well as the HUD information shown through that module with substantially no offset from the original display. Both the camera module and the HUD module are installable onto the same optical module at the same time, and can be installed on either (or in some embodiments, any) optical module.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. patent application Ser. No.10/343,581, filed Jul. 28, 2004, which is an application under 35 USC§371 based on PCT/US01/28723, having an international filing date ofSep. 14, 2001; and to U.S. patent application Ser. No. 10/250,388, filedDec. 12, 2003, which is an application under 35 USC §371 based onPCT/US01/49988, filed on Dec. 29, 2001, which claimed priority to U.S.Provisional Patent Application Ser. No. 60/258,648, filed Dec. 29, 2000.

TECHNICAL FIELD

This system relates generally to the field of optics and, moreparticularly, to a modular image enhancement system and method for nightvision goggles having removably attachable and interchangeable left andright outer and inner channels and modular components such as a heads-updisplay (HUD) and a camera.

BACKGROUND

Existing night vision systems have many applications in everyday life.Perhaps the most well known use for night vision systems is by themilitary when performing nighttime maneuvers. The night vision systemspermit vision under very low light conditions by converting incominginfrared and/or visible light from a viewed scene to an intensifiedvisible light image. During nighttime maneuvers, military personnel areoften performing other tasks, such as piloting an aircraft or driving avehicle, that require the freedom of their hands while they visuallyscan the territory. Accordingly, night vision systems have beendeveloped to be worn upon the head of a user, such as goggles beingsecured directly on the head or by being mounted to a helmet or a visor.

Placing a night vision system on the head of a user places significantconstraints upon the optical design of the system. For example, gogglesworn upon the head of a user must be both compact and light in weightbecause excessive weight or excessive front-to-back length of thegoggles can cause the goggles to exert large moments on the user's head,causing severe instability problems and preventing their effective usein applications in which the user's head may be subjected to highgravitational or centrifugal loads. Furthermore, in a wide field-of-viewoptical system, the focal length of the eyepiece optics must beshortened correlatively with that of the wide angle objective for unitymagnification. In night vision goggles, this results in insufficient eyerelief between the eyepiece optics and the eye, which not only causesdiscomfort to the user, but also interferes with the ability to positiona helmet visor, eyeglasses, and other structures between the goggles andthe eyes of the user. In order to compensate for inadequate eye relief,prior night vision goggles have generally been limited to providing afield of view of no more than about 40 degrees.

Night vision goggles have been used in military aviation for severalyears with fields of view ranging from 30 degrees (Early Cat's Eyesnight vision goggles from GEC-Marconi Avionics) to 45 degrees (NITE-OPand NITE-Bird night vision goggles, also from GEC-Marconi Avionics). Thevast majority of night vision goggles used in military aviation have a40-degree circular field of view (AN/AVS-6 and AN/AVS-9). A majorlimitation of such prior art devices is that increased field of viewcould only be obtained at the expense of resolution since each ocularuses only a single image intensifier tube and each image intensifiertube has a fixed number of pixels. Therefore, if the fixed numbers ofpixels is spread over a larger field of view, then the angular subtenseper pixel increases, which translates into reduced resolution.Understandably, increased field of view is a major enhancement desiredby military aviators, closely followed by resolution. In conventionalgoggles, both eyes also typically see the same field of view, i.e.,there is a 100-percent overlap of the image viewed by both eyes of theobserver. Such a limited field of view greatly restricts theeffectiveness of the night vision apparatus.

Night vision systems enjoying an enlarged or panoramic field of view ofup to 60 degrees or more and having improved visual acuity have beendeveloped to address this issue. Such systems include additional opticalchannels mounted adjacent the existing binocular channels to expand thefield of view without sacrificing resolution. However, such systems areexpensive and must necessarily obviate existing binocular systems whenthe user upgrades. Moreover, to upgrade from binocular to panoramiccapabilities, the old binocular systems must be discarded and replacedby new panoramic systems. For many users, even those enjoying largemilitary budgets, a large-scale upgrade thus represents a significantexpense.

Further, as it is often the case that only a few individuals needpanoramic night vision at any given time (and it is not always the samefew), it is attractive to be able to purchase and use the less expensivebinocular systems for the average user and stock only enough of the moreexpensive panoramic systems as is necessary. While it is notinconceivable to swap out panoramic night vision systems, such systemsare often helmet mounted, with the helmets being customized tocomfortably fit a single wearer. In addition, failure of any one of thepanoramic channels means that the entire unit will be out of servicewhile it is either repaired or replaced. Furthermore, the unitary designof some night vision goggles results in removal of one module affectingthe performance (mechanically, optically, and/or electrically) of theremaining module(s).

In some existing night vision systems, a heads-up display may be shownin the field of view of the user by adding the HUD graphics to theoutput of one of the image intensifier channels. The channel throughwhich the HUD is output, however, is not selectable to match thedominant eye of the user. In other systems, where the night visiongoggles are fitted with a HUD and a camera for recording the scenerybeing viewed, the systems are unable to record both the scenery beingviewed and the HUD content so that the recording matches substantiallyexactly what the user is being shown through the eyepiece.

Furthermore, many night vision systems fail to provide components thatare modular in optical, mechanical, and electrical terms, so thatremoval of one component essentially disables the system mechanically,optically, and electrically. Many existing designs fail to take intoaccount that most individuals have a dominant eye and a weaker eye, thesystems having only a predetermined side on which the heads-up displaycan be shown. Still further, existing systems do not record both theheads-up display content and scenery when a camera/recorder isimplemented.

Thus, a need still remains for a night vision system that is readilyupgradeable from binocular to panoramic field of view, wherein thepanoramic capability may be readily transferred from binocular unit tobinocular unit, and wherein the failure of any given optical module doesnot require the entire unit to be out of service for any appreciablelength of time. Various forms of the present invention address theseneeds, among others.

SUMMARY

The disclosed system and method relate to a modular, binocular-likenight vision system for enabling an observer to view an object. Thedescribed embodiment includes a pair of modular inner channels that maybe interchangeably connected to a bridge to form a base binocular unit,and a pair of modular outer channels, each of which may beinterchangeably connected to either of the inner channels to form afour-channel panoramic night vision system. The system includes aheads-up display (HUD) module and a camera module, each being removablyattached to the rest of the system. The optical channels, HUD, andcamera are optically, electrically, and mechanically modular, so thatremoval of one or more modules generally does not affect the operationof those remaining in the system. The HUD module is switchable so thatits output may be displayed through either of the inner modules, or bothof them, according to user preference or based on the dominant eye ofthe user. The camera/recording module is able to record both theintensified image transmitted through one or more of the opticalmodules, along with the additional material supplied by the HUD modulewithout substantial distortion (and preferably with no distortion) ofthe location of that material relative to the intensified image. Oneobject of the present design is to provide an improved night visiongoggle system design. Related objects and advantages of the presentdesign will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan partial sectional view of a binocular-like visionsystem.

FIG. 2 is a rear view of the binocular-like vision system of FIG. 1.

FIG. 3 schematically shows the field of view generated by thebinocular-like vision system of FIG. 1.

FIG. 4 is a front perspective view of a first embodiment, a modularpanoramic night vision goggle assembly as mounted to a helmet visor.

FIG. 5 is a front perspective view of the embodiment of FIG. 4 viewed inisolation from the helmet.

FIG. 6 is a front perspective view of the embodiment of FIG. 4 showingthe outer optical modules detached from the inner modules.

FIGS. 7 and 8 are top and rear plan views, respectively, of thebinocular-like embodiment of FIG. 6.

FIGS. 9 and 10 are top and rear plan views, respectively, of the4-channel panoramic embodiment of FIG. 4.

FIG. 11 is a perspective view of an outer optical module of FIG. 6.

FIG. 12 is a schematic view of the field of view generated by the4-channel panoramic embodiment of FIG. 4.

FIG. 13 is an enlarged perspective view of the inner left and innerright optical modules of the embodiment of FIG. 4.

FIG. 14 is an exploded view showing the separate modular elements,including a camera, forming the modular 4-channel panoramic night visionassembly of the embodiment of FIG. 4.

FIG. 15 is an exploded view of a narrow-view form of a second modularvision system.

FIG. 16 is a perspective view of a wide (panoramic)-view form of thesecond modular vision system.

FIG. 17 is an exploded view of the modular vision system of FIG. 16.

FIG. 18 is a horizontal sectional view of the modular vision system ofFIG. 16.

FIG. 19 is a vertical sectional view of an inner optical channel in themodular vision system of FIG. 16, without a camera module or a HUDmodule.

FIG. 20 is a vertical sectional view of an inner optical channel in themodular vision system of FIG. 16, with a camera module and a HUD moduleattached.

DESCRIPTION

For the purposes of promoting an understanding of the principles of theinvention and presenting its currently understood best mode ofoperation, reference will now be made to the embodiments illustrated inthe drawings. It will nevertheless be understood that no limitation ofthe scope of the invention is intended by the specific language used todescribe the invention, with such alterations and further modificationsin the illustrated device and such further applications of theprinciples of the invention as illustrated therein being contemplated aswould normally occur to one ordinarily skilled in the art.

In general, FIGS. 1 and 2 illustrate a panoramic night vision viewingsystem as described in U.S. Pat. Nos. 6,075,644 and 6,201,641, bothowned by Night Vision Corporation, a co-assignee of the presentinvention, wherein like elements are identified by like numerals. Thevision system 50 is contained in a housing assembly 52 having a pair ofhousings 54 and 56 connected to one another by way of a bridge 57 andare arranged for respectively covering the right eye 58 and the left eye60 of an observer. Each housing 54 and 56 contains identical opticalsystems that are mirror images of each other about a plane 63 (denotedby dashed lines) that bisects the housing assembly 52 as shown inFIG. 1. Accordingly, the following discussion regarding the housing 54is equally applicable to the housing 56.

As detailed in FIG. 1, housing 54 includes two separate opticalcomponents 62 and 64. The inner optical component 62 has an opticalstructure identical to that of the outer optical component 64.Accordingly, the following discussion regarding the structure of theinner optical component 62 is equally applicable to the outer opticalcomponent 64. The inner optical component 62 includes three main opticalstructures: (1) an objective optical system 66; (2) an image intensifiertube 68; and (3) an eyepiece optical system 70. The objective opticalsystem 66 typically includes approximately 6 to 8 optical elements, suchas plastic or glass lenses L, which typically have an effective focallength of approximately 25 mm, F/1.2. The lenses L of the objectiveoptical system 66 are typically spherical in design.

The objective optical system 66 further includes an input end 72,designed to receive light from an object being viewed at input end 72and to transfer an image of an object to the photocathode side 74 of theimage intensifier tube 68. The image intensifier tube 68 makes itpossible for the observer to view an object in relatively darkconditions by receiving the visible and/or infrared light image of theobject transferred from the input end 72 thereof. The image intensifiertube 68 converts the received image to an intensified visible outputimage in a predetermined narrow band of wavelengths at the output end 78of the image intensifier tube 68. The output image is emitted in greenphosphor light (known as “P-20” or “P43” light). Such an imageintensifier tube 68 is well known in the art, although it will beappreciated that other image intensifier constructions could also beused. For example, the image intensifier tube 68 may include a GaAsphotocathode at the input end 72. Vision system 50 of FIGS. 1-3generally has an input end (72, 90) that receives light from an objectand an optical transfer system (62, 64, 86, 88) that receives theintensified light received from the image intensifier tube 68 andtransfers the intensified light to an output end (80, 92) of the system,wherein light transmitted out of the output end forms an intensifiedfield of view of the object; typically, the view through system 50 isgreater than a 60 degree horizontal field of vision.

Typically, image intensifier tube 68 also includes a fiber optic bundle(schematically shown at 75) for transmitting bits of image data from thephotocathode input end 74 to the phosphor output end 78 thereof Thefiber optic bundle 75 is preferably twisted in a manner well known inthe art to provide an image rotation of 180 degrees so that an uprightimage of the object will be presented to the eye of the user.

The intensified visible output image generated by the image intensifiertube 68 is transferred to an output end 80 of the inner opticalcomponent 62 via the eyepiece optical system 70. The light transmittedthrough the output end 80 is transmitted along the optical axis 84 thatis aligned with the optical axis of the right eye 58.

In order to enlarge the field of view through system 50, an outeroptical component 64 is provided that also directs light from the objectto the observer. Like the inner optical component 62, the outer opticalcomponent 64 includes an objective optical system 66, an imageintensifier tube 68 and an eyepiece optical system 70 that operate inthe same manner as their counterparts in the inner optical component 62.Accordingly, the objective optical system 66 and the eyepiece opticalsystem 70 of the outer optical component 64 each have an effective focallength of approximately 25 mm like their counterparts in the inneroptical component 62. The input end 72 of the outer optical component 64receives light from an object. The received light is then transferredvia the objective optical system 66 to the image intensifier 68, whichin turn generates an intensified image that is received by the eyepieceoptical system 70. The eyepiece optical system 70 then sends the imageto an output end 80 of the outer optical component 64. The lighttransmitted through the output end 80 travels along an optical axis 82that is offset from the optical axis 84 by an angle typically rangingfrom approximately 30 degrees to 35 degrees, and which is more typicallyabout 30 degrees.

The inner optical component 86 for the left eye 60 has the samestructure and operates in the same manner as the inner optical component62 for the user's right eye 58. Similarly, the outer optical component88 for the left eye 60 has the same structure and operates in the samemanner as the outer optical component 64. In other words, the inner andouter optical components 86 and 88 each receive light from an object atthe input ends 90 and transfer their images of the object to respectiveoutput ends 92. As shown in FIG. 1, the image from the inner opticalcomponent 86 intensifier tube 68 is projected along an optical axis 94that is aligned with the optical axis of the left eye 60 and, thus,substantially parallel to the optical axis 84 of the right eye. Theimage from the outer optical component 88 is projected along an opticalaxis 96 that is offset from the optical axis 94 by an angle typicallyranging from 30 degrees to 35 degrees, and which is more typically about30 degrees.

As best shown in FIG. 2, the two-eyepiece optical systems 70 for each ofthe housings 54 and 56 are positioned adjacent to each other so that theimages at the output ends 80 and 92 appear continuous without anoticeable line of demarcation between the exit elements of the eyepieceoptical systems. With respect to the forward looking direction, the twoadjacent eyepiece optical systems for each housing 54 and 56 provide acontinuous horizontal field of view that begins about 50 degrees to theright (or to the left) and ends 15 degrees to the left (or to theright).

As shown in FIG. 1, the optical systems are in line with the line ofsight of the observer's eyes 58 and 60. In addition, as shown in FIG. 2,the output ends 80 and 92 may each be offset below their respectiveinput ends 72 and 90. This is accomplished by inserting well knownmirror systems or prism systems (not shown) between the output ends 78of the image intensifier tubes 68 and the eyepiece optical components70. The apparatus also includes a well known mechanism 98 in bridge 57for adjusting the interpupillary distance between the eyepiece opticalsystems in the two housings 54 and 56 to accommodate different users.

The field of view 100 generated by the light simultaneously transmittedalong the four optical axes 82, 84, 94, 96 to the observer of the system50 is shown schematically in FIG. 3. The field of view 100 is the resultof having the sub-fields of view formed from each of the output ends 80and 92, which overlap one another. Each of the four sub-fields of vieware circular, have a horizontal field of view of approximately 40degrees, and have a vertical field of view of approximately 40 degrees.The field of view 100 includes two peripheral portions 102 and 104 thatare separated from one another and that each have a monocular effect onthe observer. The field of view 100 includes an overlapping centralportion 106 spanning approximately 30 degrees. The central portion 106is positioned between the monocular portions 102 and 104 and is viewedby both eyes 58 and 60 of the observer to provide full depth perceptionand exact stereo vision in the central portion 106. The combined fieldof view 100 has a vertical field of view of approximately 40 degrees anda horizontal field of view of approximately 100 degrees.

FIGS. 4-5 present an embodiment of the present invention, a modularpanoramic night vision goggle (“MPNVG”) assembly 300, having modular,repeatably detachable/reattachable individual optical channels 310, 320,330, 340. FIGS. 4 and 5 show the MPNVG assembly 300 mounted on (in FIG.4) and unmounted from (in FIG. 5) the visor 302 of an HGU-56/P helmet304 and includes four optical channels 310, 320, 330, 340 coordinated bya bridge 350. Bridge 350 is preferably provided with a mount 365 forreleasably mounting the assembly to a helmet or visor as shown in FIG.4. Modular assembly 300 may be affixed to the visor 302 by conventionalmeans. Each of the four (4) optical channels 310, 320, 330, 340 providesimage intensifier functionality in a separately sealed andself-contained optical module generically referred to as module 345. Inpreferred embodiments, inner channel modules 320 and 330 are mirrorimages of each other and are connectable directly to the bridge 350. Insome embodiments the outer channel modules 310 and 340 are identical andinterchangeable with one another. In any of these embodiments, removalof any single module 345 from the MPNVG assembly 300 will neither breakany pressure seals nor degrade the optical, electrical, or intensifyingperformance of the removed module 345, nor of any remaining module. Whena module 345 is removed, the functionality of that channel (its opticaltransmission, HUD presentation, or information capture, for example) islost from the system, of course, but the remaining modules continue toperform their respective functions.

Electrical power and information required by a module 345 are providedthrough electrical connectors 357 between each adjacent pair of modules345, as well as between the inner modules 320, 330 and the bridge 350.Such electrical connectors 357 are typically connector port assembliesand include, in various example embodiments, spring-loaded wipercontacts 312 provided on the outer optical modules 310, 340 (as shown inbetter detail in FIG. 11) and contact pads 328, 338 provided on theinner optical modules 320, 330, respectively (as shown and discussed inrelation to FIG. 13). Likewise, the electrical connection between amodule 345 and the bridge 350 may include spring-loaded wiper contacts312 provided on the bridge 350 and contact pads 328 provided on themodule 345 and oriented to matingly connect to the wiper contacts 312when the module 345 is mechanically engaged with the bridge 350.Alternately, other types of electrical connectors 357 may be chosen toestablish module-to-module and/or module-to-bridge electricalcommunication. With any of these connector types, both power and dataare transmitted from one module to the next, and to and from bridge 350using the structures and techniques that will occur to those skilled inthe art. In some embodiments, electrical paths are provided so thatpower for all modules comes from bridge 350, passing to outer modules310, 340 and other attached modules (such as the HUD and camera modules)through the inner modules 320, 330. Parallel circuitry is preferablyprovided so that a malfunction in or damage to an inner module does notdisrupt this flow of power. Likewise, data acquired or required by eachmodule is transmitted through the electrical connectors to theappropriate destination using techniques known to those skilled in theart.

In alternative embodiments, each optical module 345 attaches directly tothe bridge 350, which provides power and data through electricalconnections as will occur to those skilled in the art. In some of theseembodiments HUD module 360 and camera 370 are attached to bridge 350,while in others they are each attached directly to an optical module345, and in the most preferred embodiments they are attached to the sameinner module 320 or 330. In any of these forms, power and data aretransferred between the components through wiper contacts and pads, pinsand sockets, suitable connectors distributed by Hirose Electric Co.,Ltd., or other electrical connection means as will occur to thoseskilled in the art.

Each module 345 includes attachment means, preferably defined bymechanical connection port 355, that ensures proper positioning andalignment of adjacently mating modules. Likewise, mechanical connectionports 355 are also provided to connect modules 345 to the bridge 350 inproper position and alignment. As shown best in FIGS. 11, 13 and 14, themechanical connection port 355 may include tongue-and-groove typeconnectors 314, 324, 334, by which each module 345 is slidably receivedby and secured to an adjacent module 345. In this embodiment, theintegral electrical connectors 357 typically present on each module 345(such as wiper contacts 312 and contact pads 328 and 338) enable theelectrical connection between adjacent modules 345 to be madesimultaneously with the mechanical attachment of the modules 345. Inother embodiments, electrical and data connections are made separatelyby way of, for example, cable connectors, fiber optic relays, or thelike extending between adjacent modules 345. In yet other embodiments,the mechanical and electrical connectors 355, 357 are unitary orcoextensive with each other. In still other embodiments, the mechanicalconnection port 355 includes one or more alignment features and arelease feature that holds the module 345 in a fixed alignment relativeto the component with which it is connected, and releases the module 345when the release feature is actuated, as is known in the camera/tripodart. In any of these embodiments, the components of system 300 areelectrically, mechanically, and optically modular.

In addition to the modularity of the four primary optical channels 310,320, 330, 340 of the MPNVG assembly 300, a removably re-attachablemodular heads-up display, or “HUD,” 360 and a removably re-attachablemodular camera 370 are included in some embodiments of the MPNVGassembly, as shown in FIG. 14. Similar to the individual optical modules345, each of these modular components 360, 370 is separately sealed andself-contained. In some embodiments, modular camera 370 is of a typeused with helmet assemblies for flight operations. When both modularcamera 370 and HUD 360 are connected in electrical communication withone or more modules 345 and each other, camera 370 is able to recordboth scenery (from the module 345) and display data (from HUD 360).Removal of HUD 360 and/or camera 370 will not break any pressure sealsor degrade the performance of the removed module 360, 370, nor of any ofthe optical modules remaining in the system. While, of course, theremaining modules would not have the benefit of the functionality of theremoved module 360, 370, the functionality of the remaining moduleswould still be provided by the system. Again, electrical power andinformation (e.g., data signals and the like) provided or required byHUD 360 or camera 370 pass through the electrical connector 357 that isprovided on each module 345, 360, 370.

A variety of data flow patterns may be used in various embodiments,depending for example on user preference, manufacturing convenience, andthe available interface(s) to the connecting system. For example, insome embodiments, data is transmitted by wired connections from theaircraft to the HUD 360, through HUD connector to the optical module 320or 330, passing through the optical module to the camera connector tocamera 370, and back through the path to HUD 360 and to the aircraft. Inalternative embodiments, the aircraft's signal cable might attach to thegoggle system at an optical module 320, 330, and be sent to the HUD 360,while the output of camera 360 travels through the optical module 320,330, to the aircraft. In still other alternative embodiments, theaircraft cable might attach to the bridge 350, which would distributeand collect signals to and from the optical module 320, 330, HUD 360,and camera 370. In yet other embodiments, communication between theaircraft and the goggle system might happen over radio frequency (RF)links using well known wireless technology.

One advantage of certain embodiments of the present invention is thatusers can attach the HUD 360 to either inner module 320, 330, so thatthe information provided by the HUD is seen by the user's dominant eye.Further, since camera 370 can be attached to either inner module 320,330, camera 370 can record precisely the combination of intensifiedimage and HUD display that the user sees through his or hercorresponding eye.

The field of view 400 generated by the light simultaneously transmittedalong the four optical axes 317, 327, 337, 347 of the optical modules310, 320, 330, 340 is schematically shown in FIGS. 9 and 12. The fieldof view 400 results from the combination of the overlapping sub-fieldsof view from the output ends of the optical modules. The field of view400 includes two monocular portions 402, 404, and a 40-degree binocularportion 406 (i.e., the central overlap portion). The field of view 400in the illustrated embodiment has a vertical field of view ofapproximately 40 degrees and a total horizontal field of view ofapproximately 100 degrees.

In some embodiments, the outer optical modules 310, 340 are identicaland interchangeable. In some forms, such a module 310, 340 may be simplyturned about its longitudinal axis to serve as either the right outermodule 310 or left outer module 340. The right inner module 320 and leftinner module 330 may be identical and interchangeable, or may bedesigned as mirror images of each other. In other forms, the module 310,340 are identical, and can be removed and transposed between theleft-outer position and the right-outer position as necessary ordesired. In an alternative embodiment, all of the modules 345 (right andleft, inner and outer) may be designed to be identical and universallyinterchangeable; i.e., any given optical module 345 may serve as a rightor a left inner module or as a right or left outer module.

A significant advantage provided by complete modularity in someembodiments is that one can employ, if desired, the dual-channelembodiment of this assembly as shown in FIGS. 7 and 8, comprising onlythe inner optical modules 320, 330 and the bridge 350. One can then addHUD 360 and camera 370 if desired. This allows an end user to purchaseonly the dual-channel modular version of the invention as its financespermit and, as needed or as finances permit, to purchase separatelyadditional universal optical modules 345 connectable as outer modules310, 340 to convert the dual-channel unit to a 4-channel panoramic unit.This availability is particularly beneficial for developing countrieswith limited military budgets. This also allows the dual-channelassembly to be used by persons who need no- or low-light visibility, butwho do not need panoramic capability, such as aircraft or ground crewother than the pilot(s). Further, this embodiment allows additionalouter modules 310, 340 to be redistributed to selectively upgradedual-channel systems as needed, allowing the acquisition of relativelyfew outer channel modules 310, 340 to effectively upgrade a much largernumber of dual-channel units (where not all are required tosimultaneously function as panoramic units.)

From an operations standpoint, each optical module 345 is designed toreceive light from an object being viewed at an input end 311, 321, 331,341, and to transfer an image of the object to the input end of aninternal image intensifier (not shown). The image intensifier makes itpossible for the observer to view an object in dark conditions byreceiving the visible and/or infrared light image of the objecttransferred to the input end thereof. The image intensifier converts thereceived image to an intensified visible output image in a predeterminednarrow band of wavelengths at its output end. For example, the imageintensifier may include a GaAs photocathode at its input end. An opticaltransfer system transfers the received light to an output end 313, 323,333, 343 of each module.

Another embodiment, goggle system 500, is shown in FIGS. 15-20. FIG. 15illustrates a narrow-view (inner modules only) night vision gogglessystem 500. The system attaches with ANVIS mount 510 to a pilot'shelmet, which supports the structure in a position suspended before thepilot's eyes. ANVIS mount 510 holds a bridge 515 in a fashion thatallows adjustment of the goggle, either closer to or further away fromthe pilot's eyes, tilting the optical channels up or down, and changingthe interpupillary distance. Bridge 515 supports optical modules 520 and522, which provide intensified imaging for the pilot's left and righteyes, respectively. In this 2-optical-channel embodiment, physical andelectrical connectors at 524 are not needed to secure, power, andcommunicate with outer channels, so each outer side of inner modules520, 522 is covered with a side cover 526.

Each of the inner modules 520, 522 includes a port 528 to which a cameramodule 530 can be attached. As shown in FIG. 15, camera module 530 canbe placed into port 528 of right inner module 522 so that camera module530 records what is seen by the pilot through his or her right eye. Theoptical operation of this view capture will be discussed in more detailbelow. The camera port cover 532 provides no recording functionality,but fits into port 528 of left inner module 520 to protect it fromdamage and foreign particles.

Similarly, this HUD module 534 connects to HUD port 535 on the bottomside of optical module 522. HUD module 534 adds a heads-up display tothe image seen by the user and recorded by camera module 530 (if it isinstalled). Bottom port 535 of optical module 520 is covered by HUD portcover 536, providing protection from foreign objects and light, andagainst physical damage to the port 535 and/or optical channel 520.

FIG. 16 shows system 550, which expands the narrow-view system 500 intoa wide (panoramic) form 550. As in FIG. 15, bridge 515 supports innermodule 520 and outer module 522, and inner module 522 is fitted withcamera module 530 and display module 534. Left inner module 520 hascamera port 528 and HUD port 535 covered with camera port cover 532 andHUD port cover 536, respectively, as also seen in FIG. 15. In panoramicsystem 550, however, outer channel 540 is attached to left inner channel520, and another outer channel 540 is attached to right inner channel522, altogether providing the panoramic, intensified view discussedabove. It is noted that camera 530 and HUD 534 can each be placed in thecorresponding port on either inner module 520, 522. This flexibilityallows a pilot to have the HUD display from HUD module 534 shown to hisor her dominant eye, while retaining the ability to capture theintensified image and HUD concurrently with substantially perfectregistration (of the HUD display on the intensified image) relative towhat the user sees.

FIG. 17 illustrates the same system as 550 in an exploded view. Hereconnectors 524 on the outer sides of inner modules 520 and 522 can beseen in position for receiving outer module 540. Similarly, camera port528 and display port 535 are shown in condition for receiving camera 530(or camera port cover 532) and HUD 534 (or lower port cover 536),respectively.

FIG. 18 is a horizontal cross-section of a panoramic system similarlyshown in FIG. 15. In each optical module 520, 522, and (both) 540s, anobjective lens system 552 collects light from the field of view andfocuses it on image intensifier and image intensifier 554. Imageintensifier 554 converts the received light into an intensified imageused in techniques known to those skilled in the art, and transmits theintensified image through cavity 556 to eyepiece lens 558. While eachoptical module 520, 522, 540 includes cavity 556 between imageintensifier 554 and eyepiece lens 558 (providing a common housing andassembly design up to that point), inner optical modules 520 and 522also include pellicle 560 in that cavity as will be discussed below. Thedesigns of the inner and outer modules in some embodiments are the sameexcept for placement of this pellicle 560, making for efficientmanufacturing operation.

In the illustrated embodiment, pellicle 560 is a very thin (2 to 10micron) membrane made of nitrocellulose or similar material. Thatmaterial is bonded to a flat (lapped) ceramic or metal frame. While thinglass or glass prism combiners might be used, pellicle-type combinersare typically lighter in weight and very simple to use in the opticalpath of an eyepiece assembly. Because of their thinness, pellicles canbe added to an optical system without any significant optical effect. Inthe present embodiment, each of the two inner channels 520, 522 has apellicle-type combiner, while the two outer channels 540 do not, andthey are all otherwise optically identical as shown in FIG. 18. Inalternative embodiments using prism type combiners, a different opticaldesign that compensates for the combiner's thickness would be requiredfor the eyepieces and the system would be much longer and heavier.

Pellicle-type combiners are further preferred because ghost images areessentially eliminated by the thinness of the pellicle membrane as thesecond surface reflection is superimposed on the first surfacereflection. In addition, the pellicles can be coated to reflect anydesired wavelengths or, if left un-coated, will reflect approximately 8%and pass 92% of the incident light energy, as used in this embodiment.Because of thinness of the pellicle, the reflected images from thedisplay to the eye and from the intensifier to the camera are reflectedfrom the same surface and appear to be identical because they providesubstantially identical relative positioning for the recorded image ascompared to an image seen by the user. The prism type combiner cannotprovide same position as pellicle type.

Each optical module, including outer, may include mounts for thepellicle, camera port and HUD port, but otherwise be substantiallyidentical.

FIG. 19 is a side-sectional view of right inner optical module 522illustrating optical paths and some attachment features of the presentembodiment. As discussed above, in relation to FIGS. 16-18, ANVISattachment 510 connects the pilot's helmet to bridge 515, which in turnsupports the remaining structures in goggle system 550. Light entersoptical module 522 from the right centered about optical axis 562,passing first through objective lens system 552 to image intensifier554. Image intensifier 554 intensifies the image and retransmits itfurther to the left into cavity 556 and to pellicle 560. Part of thelight from image intensifier 554 is reflected by pellicle 560 and exitson housing of optical channel 522 at camera port 528. The rest of thelight from image intensifier 554 continues through eyepiece lens 558 tothe user.

Similarly, when HUD module 534 (FIG. 17) is in place, the HUD displayenters optical module 522 through HUD port 535 along optical axis 564.Part of the light is reflected off pellicle 560 to the user alongoptical axis 562, while the rest continues through pellicle 560 andcamera port 528 along optical axis 264 to camera module 530 when cameramodule 530 is present.

FIG. 20 is another side-sectional view of optical module 522, withcamera module 530 and HUD module 534 as shown in FIG. 16. In FIG. 20, asin FIG. 19, light enters the optical module 522 from the right throughobjective lens system 552 to image intensifier 554. The intensifiedimage continues to the left along axis 562, and is split by pellicle 560so that a portion of the light reflects upward through camera port 528into camera module 530, while the rest continues along axis 562 througheyepiece lens 558 to the user.

Meanwhile, in the illustrated embodiment, HUD module 534 generates aheads-up display using organic light-emitting diode (OLED) type displaychip 533, and reflects the display image off prism 566 onto optical axis564 and through HUD port 535. When the HUD display reaches pellicle 560,a portion of the light is reflected onto optical axis 562 to the user'seye, while the remaining light proceeds through camera port 528 tocamera module 530.

It will be observed that the intensified image and HUD image appear atthe user's eye and at camera module 530 in substantially the samealignment by operation of pellicle 560. This substantially perfectregistration is very beneficial to those evaluating the performance ofthe pilot, the night vision system, the aircraft, and armaments thathave been deployed, for example.

In operation, the field of view of dual-channel night vision goggles(i.e., having two substantially parallel inner optical modules) may beincreased by

-   -   selecting an inner optical module    -   finding the inner module mechanical connection port 355 on the        inner optical module    -   finding the inner module electrical connector 357 on the inner        optical module    -   selecting an outer optical module that has an outer module        mechanical connection port 355 and an outer module electrical        connector 357    -   connecting the inner module mechanical connection port 355 with        the outer module mechanical connection port 355, and    -   connecting the first inner module electrical connector 357 with        the outer module electrical connector 357.

Repetition of this process to add an outer module 340 to the otherchannel 330 results in the field of vision of the unit 300 beingexpanded panoramically to the left and the right.

Likewise, a damaged unit (such as one having a damaged or broken opticalmodule 345) may be repaired by

-   -   severing the mechanical connection between the broken optical        module and the rest of the night vision system    -   severing the electrical connection between the broken optical        module and the rest of the night vision system    -   mechanically connecting a replacement optical module to the        night vision system, and    -   electrically connecting the replacement optical module to the        night vision system.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character. It is understood that theembodiments have been shown and described in the foregoing specificationin satisfaction of the best mode and enablement requirements. It isunderstood that one of ordinary skill in the art could readily make anigh-infinite number of insubstantial changes and modifications to theabove-described embodiments and that it would be impractical to attemptto describe all such embodiment variations in the present specification.Accordingly, it is understood that all changes and modifications thatcome within the spirit of the invention are desired to be protected.

1. A night vision goggle system, comprising: a bridge; and two or moreoptical modules, each providing image intensifier functionality, andeach comprising: a housing having a first end and a second end; and animage intensifier situated in the housing that receives energy throughthe first end and passes an intensified image out through the secondend; wherein at least one of the optical modules is removably attachableto the bridge; and when two or more of the optical modules are attachedto the bridge and one of them is removed from the bridge, the removaldoes not detrimentally affect the image intensifier functionality of anyof the others.
 2. The night vision goggle system of claim 1, wherein:each of the two or more optical modules receives electrical power from apower source via the bridge; when two or more of the optical modules areattached to the bridge and one of them is removed from the bridge, theremoval does not disrupt the electrical supply to any of the others. 3.The night vision goggle system of claim 1, wherein each of the two ormore optical modules is an inner module that is mechanically connectedto the bridge, further comprising: at least one outer optical module,each removably attached to the system, each performing image intensifierfunctionality, and each comprising: a housing having a first end and asecond end; and an image intensifier situated in the housing thatreceives energy through the first end and passes an intensified imageout through the second end; wherein, when one of the outer opticalmodules is removed from the system, the removal does not detrimentallyaffect the image intensifier functionality of any other optical module.4. The night vision goggle system of claim 3, wherein at least one ofthe at least one outer optical module is physically attached to an innermodule.
 5. The night vision goggle system of claim 1, further comprisinga heads-up display module removably attachable to at least one item inthe group consisting of: the bridge, and the two or more opticalmodules; wherein, when the heads-up display module is removed from theitem to which it is attached, the removal does not detrimentally affectthe image intensifier functionality of any of the optical modules. 6.The night vision goggle system of claim 5, wherein the heads-up displaymodule: is contained within a housing that is separable from the item towhich it is attached; comprises an electrical connector; obtains powerthrough the electrical connector from the other components in the systemwhen the heads-up display module is connected to the item.
 7. The nightvision goggle system of claim 1, wherein each of the two or more opticalmodules is an inner module that is mechanically connected to the bridge,further comprising: at least one outer optical module, each removablyattached to a respective inner module, each performing image intensifierfunctionality, and each comprising: a housing having a first end and asecond end; and an image intensifier situated in the housing thatreceives energy through the first end and passes an intensified imageout through the second end; wherein the at least one outer opticalmodule is adapted to be removably attached to either of the innermodules.
 8. The night vision goggle system of claim 1, wherein the twoor more optical modules are identical.
 9. A night vision goggle system,comprising: at least two optical channels, including a first opticalchannel and a second optical channel, each adapted to provide alight-intensified image to a user, and together providing a stereoscopicview of an object; and a heads-up display generator in communicationwith at least one of the first optical channel and the second opticalchannel, wherein the heads-up display generator generates HUD signalsusable by an optical channel to augment the light-intensified image witha superimposed display of information; wherein the superimposed displayis switchable between the first optical channel and the second opticalchannel.
 10. The night vision goggle system of claim 9, wherein thesuperimposed display is also switchable to be added simultaneously toboth the first optical channel and the second optical channel.
 11. Thenight vision goggle system of claim 9, adapted so that the first opticalchannel is viewed with the left eye of a user and the second opticalchannel is viewed with the right eye of the user.
 12. The night visiongoggle system of claim 9 wherein: the heads-up display generatorcomprises an electrical connector adapted to removably engage acorresponding connector in the system to form an electrical circuit; andthe HUD signals pass through the electrical connector.
 13. The nightvision goggle system of claim 12, wherein: the first optical channel andthe second optical channel are each housed enclosed in a housing thatcomprises an electrical connector; the heads-up display generatorcomprises an electrical connector adapted to removably engage theelectrical connector of either the first or the second optical channel;when the heads-up display generator is engaged with the housing of thefirst optical channel, the display of information is superimposed on thefirst optical channel; and when the heads-up display generator isengaged with the housing of the second optical channel, the display ofinformation is superimposed on the second optical channel.
 14. A nightvision goggle system, comprising: at least two optical channels, eachadapted to provide a light-intensified image to a user; a heads-updisplay generator, in communication with at least a first one of theoptical channels, that generates HUD signals usable by the opticalchannel to augment the light-intensified image with a superimposeddisplay of information; and a camera, in communication with the heads-updisplay generator and at least the first one of the optical channels,that records information sufficient to reconstruct the light-intensifiedimage and the superimposed display of information with less than apredetermined offset in alignment relative to the original superimposeddisplay.
 15. The night vision goggle system of claim 14, wherein: theintensified image and the superimposed display are produced in discretepixels; and the predetermined offset is measured in pixels.
 16. Thenight vision goggle system of claim 14, wherein: the first one of theoptical channels has an optical axis; and the predetermined offset ismeasured in terms of the relative angle from the optical axis of thechannel.
 17. A method for increasing the field of view of binocularnight vision goggles having a first inner optical channel and a second,substantially parallel inner optical channel, wherein each inner opticalchannel has a mechanical connection port and an electrical connector,comprising: providing a first outer optical module having a first outermodule mechanical connection port and a first outer module electricalconnector; operationally connecting the mechanical connection port ofthe first inner optical channel to the first outer module mechanicalconnection port; and operationally connecting the electrical connectorof the first inner optical channel to the first outer module electricalconnector.
 18. The method of claim 17 further including: providing asecond outer optical module having a second outer module mechanicalconnection port and a second outer module electrical connector;operationally connecting the mechanical connection port of the secondinner optical channel to the second outer module mechanical connectionport; and operationally connecting the electrical connector of thesecond inner optical channel to the second outer module electricalconnector.
 19. A method for repairing a modular panoramic night visiongoggle system that comprises a plurality of mechanically andelectrically connected optical modules, comprising: severing themechanical connection between a broken optical module and the rest ofthe night vision goggle system; severing the electrical connectionbetween the broken optical module and the rest of the night visiongoggle system; mechanically connecting a replacement optical module tothe night vision goggle system; and electrically connecting thereplacement optical module to the night vision goggle unit.
 20. An outeroptical module for attachment to a binocular vision assembly to enablingan observer to view an object under low-light conditions, the assemblyincluding a pair of inner optical channels defining a binocularhorizontal field of view and substantially parallel first and secondoptical axes, the outer module comprising: a housing defining an outermodule input end that receives light from the object, and defining anouter module output end that emits light to an eye of the observer; animage intensifier in optical communication with the input end and theoutput end, the image intensifier converting incoming infrared and/orvisible light to an intensified visible image for emission through theouter module output end; and a mechanical attachment feature on thehousing for removably coupling the housing to the binocular visionassembly in a predetermined relative alignment and position; wherein themechanical attachment feature includes an electrical connector betweenthe outer optical module and the binocular vision assembly to enableelectric communication therebetween when the mechanical attachmentfeature is engaged; wherein the outer module output end defines an outermodule optical axis along which light received from the outer moduleinput end is transmitted; wherein, when the outer module isoperationally coupled to the binocular vision assembly, lighttransmitted along the first, the second, and the outer module opticalaxes is simultaneously transmitted from the vision assembly to theobserver and forms a field of view comprising a vertical field of viewof at least 35 degrees and a horizontal field of view wider than thebinocular horizontal field of view.
 21. A modular vision assembly forpresenting a user with a panoramic view of low-lit objects, comprisingin combination: a pair of substantially parallel inner optical modules,each inner optical module having: an inner module input end forreceiving light from an object, an image intensifier receiving lightfrom the inner module input end, an inner module output end forreceiving light forming an intensified image from the image intensifier,an inner module mechanical connection port that mechanically connectsthe inner optical module to the assembly, and an inner module electricalconnector that electrically connects the inner optical module to theassembly, wherein the inner module output end defines an inner moduleoptical axis along which light received from the first inner moduleinput end is transmitted from the assembly, a pair of outer opticalmodules, each having: an outer module input end for receiving light fromthe object, an image intensifier receiving light from the outer moduleinput end, an outer module output end for receiving light forming anintensified image from the, a first outer module mechanical connectionport that mechanically connects the outer optical module to theassembly, and an outer module electrical connector that electricallyconnects the outer optical module to the assembly, wherein the outermodule output end defines an outer module optical axis along which lightreceived from the image intensifier is transmitted, and a bridgeextending between and mechanically connected to the pair of inneroptical modules; wherein each outer optical module is removablyseparable from the modular vision assembly.
 22. The assembly of claim21, wherein the first outer module mechanical connection port of eachouter module is removably attachable to the inner module mechanicalconnection port of either of the pair of inner optical modules in apredetermined alignment relative to that inner module.
 23. The assemblyof claim 21, wherein the first outer module mechanical connection portof each outer module is removably attachable to the bridge in apredetermined alignment relative to at least one of the inner modules.24. The assembly of claim 23, wherein: each outer optical module furthercomprises a second outer module mechanical connection port; and thesecond outer module mechanical connection port is removably connectableto the inner module mechanical connection port of either of the inneroptical modules.
 25. The assembly of claim 21, wherein each inneroptical module is substantially identical to each outer optical module.26. A monocular optical module for attachment as part of a multiocularvision assembly for enabling an observer to view an object underlow-light conditions, the unitary optical module comprising: a housinghaving a first end and a second end; and an image intensifier situatedin the housing that receives energy through the first end and passes anintensified image out through the second end for presentation to theeyes of the observer; first mechanical attachment means for repeatedlyremovably connecting the housing to a bridge in one of a plurality ofpredetermined alignments relative to the bridge; and first electricalattachment means for providing electric communication between theoptical module and the bridge whenever the first mechanical attachmentmeans is connecting the housing to the bridge.
 27. The monocular opticalmodule of claim 26, further comprising: second mechanical attachmentmeans for repeatedly removably connecting the housing to a secondoptical module; and second electrical attachment means for providingelectric communication between the optical module and the second opticalmodule.
 28. The monocular optical module of claim 26, in a systemfurther comprising a camera for recording intensified images output fromthe optical module over time, the camera including: a camera connectoradapted to mechanically, removably attach to the second mechanicalattachment means, and to electrically, removably attach to the secondelectrical attachment means.
 29. A night vision goggle system,comprising: a first optical channel passing through a first housing andproviding a first intensified image stream to a user's first eye; asecond optical channel passing through a second housing and providing asecond intensified image to the user's second eye; a heads-up displaygenerator, removably attached to the first housing, that generates anoverlay that is combined with the first intensified image stream forview by the user; and a video capture device, removably attached to thefirst housing, that captures both the overlay and the first intensifiedimage stream.
 30. The night vision goggle system of claim 29, whereinthe second housing is adapted: to retain the heads-up display generatorin a first predetermined position and orientation relative to the secondhousing; and to retain the video capture device in a secondpredetermined position and orientation relative to the second housing;so that both the heads-up display generator and the video capture devicecan also be removably attached to the second housing.
 31. The nightvision goggle system of claim 30, wherein: the first predeterminedposition and orientation is different from the second predeterminedposition and orientation so that both the heads-up display generator andthe video capture device can be removably attached to the second housingat the same time.